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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Geoffrey Knight Psychosurgical Unit admits patients on a regular basis and thus offers special opportunities for studying severely ill psychiatric cases, all having one particular treatment under relatively controlled conditions. The opportunity has been taken to repeat various metabolic studies previously reported to be abnormal in some psychiatric illnesses. In the present investigation several measures of endocrinological activity were studied, as was plasma tryptophan, both free and bound. None of these data confirmed reports of abnormalities and neither did the values found at operation help to predict clinical outcome 1 year later, which was another possibility. Urinary catecholamines were also measured and 2 weeks after operation. Male patients, regardless of diagnosis, showed a mean increase in adrenaline output after operation compared with the pre-operative value and this was significantly different from the females, who showed a small mean decrease. The depressed patients showed a significant reduction in noradrenaline excretion after operation compared with before operation and this trend was enhanced in those of good outcome at 1 year, the difference from those who responded poorly being significant. It could be that the ventromedial lesion that is produced alters noradrenaline metabolism or autonomic activity in depression and this possibility merits further study.
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PMID:Studies of endocrine activity, plasma tryptophan and catecholamine excretion on psychosurgical patients. 33 73

The dopamine theory of depression was studied by assessing the effect of antidepressant drugs on uptake of dopamine, noradrenaline, and serotonin in synaptosomes from rat brain. Five newer drugs--butriptyline, maprotiline, trimipramine, iprindole, and mianserine--exhibited rather potent inhibition of 3H-dopamine uptake in corpus striatum, as their IC50 values, which were in the order of 10(-6)-10(-5) M, were only about 50 times higher than for nomifensine (IC50 = 10(-7) M). The five drugs were weak, compared to chlorimipramine, on 14C-serotonin uptake in the whole forebrain, as their IC50 were about 10(-5) M. Butriptyline, trimipramine, and iprindole were very weak uptake inhibitors of 3H-noradrenaline in the occipital cortex. Their IC50 values were about 10(-6) M, which is almost 1000 times higher than for desmethylimipramine. These results are discussed in relation to comprehensive recent literature as further indicating a link between dopamine and depression.
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PMID:Uptake inhibition of biogenic amines by newer antidepressant drugs: relevance to the dopamine hypothesis of depression. 40 61

The tyramine-dose/pressor response test was carried out on a series of patients suffering from primary depressive illness before and during treatment with amitriptyline. The severity of their depression was assessed during the study of the Hamilton Rating Scale (HRS). The decreased tyramine sensitivity induced by the drug, which is related to the inhibition of NA reuptake, correlated significantly with the plasma concentration of nortriptyline. However, contrary to the expectation of the noradrenaline hypothesis of depression, the decreased tyramine sensitivity, i.e., the degree of NA-reuptake blockade, did not show any correlation with clinical improvement following 6 weeks' treatment with amitriptyline.
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PMID:Noradrenaline, depressive illness, and the action of amitriptyline. 41 61

T wave and ST segment abnormalities in 20 asymptomatic men aged 18 to 55 were investigated because they were identical with myocardial ischaemic changes, and the professional livelihood of the subjects was jeopardised. Coronary arteriograms showed unobstructed arteries in all except one in whom a 50 per cent lesion of the left anterior descending artery was present. Left ventricular angiograms showed a normal contraction pattern, Ejection fractions were normal in 12 and increased in 8. Three characteristic electrocardiographic patterns were observed: flat or inverted T waves in leads II, III, aVF, and V4 to 6 designated type 1; deep T inversion particularly evident in leads V2 to 5 designated type 2, and minor ST segment depression in the inferior and lateral leads without T changes designated type 3. Characteristically, type 1 changes were temporarily suppressed by either beta-blockade or an overnight rest and were more abnormal in the standing position. Type 2 and 3 changes were relatively uninfluenced by these manoeuvres. Maximal treadmill exercise tests were positive in 6 and borderline or negative in 14. When repeated after oxprenolol all tests were negative. Echocardiograms showed asymmetric septal hypertrophy in 3 subjects (ratio of greater than 1.5 between ventricular septum and posterior left ventricular wall). After normalisation by an overnight rest, type 1 T wave abnormalities were reproduced by intravenous adrenaline infusion (0.024 to 0.18 microgram/kg/min) but not by noradrenaline or by adrenaline after prior administration of oxprenolol. When the T waves had remained deeply inverted before infusion despite rest (type 2) adrenaline infusion normalised them and again noradrenaline was without effect. This effect was also prevented by oxprenolol. Type 3 changes were uninfluenced by catecholamine infusion. Plasma catecholamine estimations suggest that catecholamine hypersecretion and hypersensitivity may both be relevant, particularly the latter. The apparent bimodal response of the ventricular myocardium to adrenaline infusion is not surprising since in vitro experiments suggest that reversal of T wave polarity in either direction may result from summation of changes in action potential duration in different parts of the heart. Such changes may be unimodal, that is both areas involved show lengthening or shortening of action potential duration, but by occurring at different rates may lead to a bimodal change in the differences in duration which generate the T wave.
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PMID:Electrocardiographic changes resembling myocardial ischaemia in asymptomatic men with normal coronary arteriograms. 42 66

Adenosine and AMP (5'-adenosine monophosphate) applied by microiontophoresis produced depression of neuronal firing rates in cerebral cortex. A number of antidepressant drugs including examples which are known not to affect noradrenaline uptake systems, potentiated the depressant purine effects. Noradrenaline responses were unaffected or reduced. Purines may therefore be important in the mechanism of action of antidepressant drugs.
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PMID:Antidepressant drugs potentiate suppression by adenosine of neuronal firing in rat cerebral cortex. 43 90

Studies of depression associated with oral contraceptive use present conflicting results. Individual susceptibility may affect psychiatric symptoms more than biochemical composition of the pill. In the authors' study 40 women without previous histories of depression were assigned to 4 regimens: 1) mestranol 80 mcg, norethisterone 1.0 mg; 2) pill 1 and pyridoxine; 3) mestranol 5 mcg, norethisterone 1.0 mg; and 4) pill 3 and pyridoxine. Alcohol and other chemicals were avoided. The 40 subjects completed self-reporting ratings on depression and a libido rating. 24 hour urine samples were collected on day 14 and 21 of the menstrual cycle. A brief psychiatric interview was conducted monthly. Adrenaline, noradrenaline, and 5 HIAA were measured throughout the year long study. 10 women completed 3 cycles. 20 of 10 complained of lethargy, loss of libido, irritability, and moodiness. The study concludes that biochemical and pharmacological effects affect a minority of women. A psychologic and negative placebogenic effect is possible. Depending on the composition of the contraceptive, a differential effect may occur. Sequential pills caused less depression than combination types.
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PMID:Oral contraceptives and depression. 44 Dec 35

Interactions between some substances (theophylline, noradrenaline, imidazole, ouabain and verapamil) and adenosine or adenosine triphosphate (ATP) were examined by recording the twitch tension of partially magnesium blocked phrenic-rat diaphragm preparations stimulated indirectly. Theophylline (an inhibitor of phosphodieterases) prevented and reversed the neuromuscular depression induced either by adenosine or ATP, and these substances antagonized the neuromuscular facilitation caused by imidazole (an activator of phosphodiesterases); noradrenaline and ouabain did not modify and verapamil increased that depression. These results indicate that the putative purine presynaptic receptor is not the ATPase, that it does not appear to operate by implication of cyclic AMP, but that it could mediate a process involved in the reduction of transmitter release by regulating the entry of calcium that follows the depolorization of the motor nerve endings.
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PMID:Purine effects at the neuromuscular junction and their modification by theophylline, imidazole and verapamil. 47 9

Nomifensine is a tetrahydoisoquinoline antidepressant which is chemically unrelated to the tricyclic or tetracyclic antidepressants, the monoamine oxidase inhibitors or the recently introduced agents. Nomifensine resembles the tricyclic antidepressants in many of its pharmacological effects in animal models of depressive illness, but differs from them in that it strongly inhibits the re-uptake of dopamine as well as noradrenaline and is a relatively weak inhibitor of serotonin uptake. It has an overall efficacy comparable with that of imipramine and amitriptyline in depressive illness, but at dosages which have achieved a similar overall clinical improvement, nomifensine causes little or no sedation, fewer and milder anticholinergic side effects, and also appears less likely than these drugs to cause serious cardiotoxicity on overdosage. Nomifensine may aggravate the psychopathology of patients with schizo-affective disorders and intensification of the psychosis may require neuroleptic therapy. Nomifensine also has antianxiety activity, but its role in treating anxiety associated with primary depression has still to be clarified. Nomifensine appears to be well tolerated by the elderly.
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PMID:Nomifensine: A review of its pharmacological properties and therapeutic efficacy in depressive illness. 47 72

Intraventricularly administered histamine (HI) (20--1000 micrograms) decreased noradrenaline (NA) .level in rat hypothalamus. 4-Methyl-HI (4-MeHI), but not 2-pyridylethylamine (2-PEA), reproduced the action of HI. Neither HI, nor 4-MeHI induced depression of hypothalamic NA content was antagonized by HI H2-receptor antagonists, cimetidine or metiamide. Chloropyramine reversed the NA-depleting action of HI.
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PMID:The action of histamine, histamine H1-and H2-receptor agonists on noradrenaline level in rat brain. 49 77

1-Norepinephrine was infused continuously for 10 hr into 5 normotensive, male laboratory subjects (mean age, 32.4 +/- 1.9 yr) at a mean rate of 0.06 microgram/kg/min. Mean plasma norepinephrine (NE) rose from the preinfusion level of 0.19 +/- 0.02 microgram/l to a steady state level of 1.22 +/- 0.29 microgram/l. The mean increase in blood pressure was 21.8 +/- 0.9 mm Hg systolic and 14.1 +/- 1.0 mm Hg diastolic. The mean depression in heart rate was 12.7 +/- 1.7 beats/min. The clearance of norepinephrine ranged from 27.9 to 100.0 ml/kg/min (mean. 58.0 +/- 13.8) and was little influenced by acute hemodynamic changes. The volume of distribution ranged widely (0.09 to 0.40 l/kg), the mean value being 13.51 1. The mean norepinephrine half-life was brief, ranging from 1.45 to 2.9 min (mean, 2.09 +/- 0.34 min). There was no evidence of a slowly accumulating high-capacity low-affinity pool of norepinephrine. These results support the use of plasma norepinephrine as an index of sympathetic activity within an individual but not its validity in interindividual comparisons.
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PMID:Interindividual variation in kinetics of infused epinephrine. 49 9


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